This invention relates to machines for rapidly and accurately filling large, bulk material bags. More specifically, the present invention is drawn to a novel spout mechanism for securely holding an open mouth of a bulk material bag during filling and for twisting the open mouth of the bulk material bag closed prior to sealing the open mouth of the bag.
1. Field of the Invention
Bulk bags are a simple and desirable means for transporting large quantities of materials. Bulk bags are available in myriad sizes, shapes and materials and may be used to transport such things as dry chemicals, building materials, food items such as flour, feeds, and the like. These bags take up little space when empty and are sufficiently strong to contain and transport quantities of materials on the order of two thousand pounds. Bulk bags are best suited for the transport of flowable materials that can be essentially poured into a bag through its top. Though possible, bulk bags are not generally used to transport liquids. FIG. 1 illustrates a typical prior art bulk bag 14 of the type that may be filled by the present invention.
As can be seen in FIG. 1, a bulk bag 14 has an outer shell 14a with a plurality of bag support loops 18a sewn to its upper surface. The outer shell 14a of the bulk bag 14 has an opening in its upper surface through which extends an elongated neck 18 or top of an inner liner 19. The inner liner has substantially the same shape as the outer shell 14a. The outer shell 14a generally is arranged to resist the majority of the pressure applied to the bag wall by the material that fills the bag 14. The inner liner of the bag 14, on the other hand, acts as a membrane to prevent the material filling the bag 14 from escaping through the walls of the bag 14. The materials from which the inner liner and the outer shell 14a are made are selected to resist degradation due to the nature of the commodities that may be placed in the bags 14. The neck 18 of the inner liner may be of any useful shape or size and is typically sized to permit fast filling of the bag 14. The bag support loops 18a are typically utilized to support the bulk bag 14 during filling, with the bag being placed on a pallet P for movement, storage, and shipment after the bag 14 has been filled.
2. Representative Prior Art
Bag filling machines of the prior art as exemplified by U.S. Pat. Nos. 4,676,284 and 5,036,983, have been drawn to the problem of hanging a bag 14 from a number of bag hanging hooks 18a and have neglected the problem of closing the neck 18 of the bags 14 to seal up the contents of the bag 14. In general, the closing of the tops or necks 18 of filled bulk bags 14 has been a manual operation requiring an operator of a bulk bag filling machine to close or seal the top of the inner liner of a bulk bag by hand using twist ties or other suitable closures. This practice is not only time consuming and strenuous for an operator of a bulk bag filling machine, but the operator may also be exposed to the contents of the bulk bag being filled.